Buckner and the officer were in the middle of a standoff -- it ended when Buckner cycled a round from his .45-caliber semi-automatic pistol and shot himself in the head.

Thinking the round fired by Buckner was at him, the officer fired back, hitting Buckner in the torso.

Buckner's neighbors describe him as erratic -- local TV station spoke with Kellie Olson, who lives down the street from him, and gives the following account.

"All I've been told is that he's threatened a lot of people in here. He's been in trouble, and cops have been called on him several times," Olson tells 3TV.

An autopsy revealed that Buckner was killed by the shot to the head. The wound on his torso was "potentially survivable," the medical examiner determined -- assuming Buckner hadn't also shot himself in the head, that is..